Preparation and characterization of solid dispersion using a novel amphiphilic copolymer to enhance dissolution and oral bioavailability of sorafenib

Evaluation of a temperature-responsive magnetotocosome as a magnetic targeting drug delivery system for sorafenib tosylate anticancer drug

In this investigation, a polymeric fusion of chitosan (CS) and thermosensitive poly (N-isopropyl acrylamide) - PNIPAAm - encapsulated a magnetotocosome, biocompatible nanocarrier. This encapsulation strategy demonstrated improved drug entrapment efficiency, achieving up to 98.8 %. Additionally, it exhibited extended stability, optimal particle dimensions, and the potential for industrial scaling, thus facilitating controlled drug delivery of sorafenib tosylate to cancerous tissue. Reversible Addition-Fragmentation Chain Transfer (RAFT) techniques were employed to synthesize PNIPAAm. The effects of polymer molecular weight and polydispersity index on the lower critical solution temperature (LCST) were evaluated. The resulting polymeric amalgamation, involving the thermosensitive PNIPAAm synthesized using RAFT techniques and CS that coated the magnetotocosome (CS-Raft PNIPAAm-magnetotocosome) with an LCST approximately at 45 °C, holds the potential to enhance drug bioavailability and enable applications in hyperthermia treatment, controlled release, and targeted drug delivery.

Amorphous solid dispersion augments the bioavailability of phloretin and its therapeutic efficacy via targeting mTOR/SREBP-1c axis in NAFLD mice

The escalating incidences of non-alcoholic fatty liver disease (NAFLD) and associated metabolic disorders are global health concerns. Phloretin (Ph) is a natural phenolic compound, that exhibits a wide array of pharmacological actions including its efficacy towards NAFLD. However, poor solubility and bioavailability of phloretin limits its clinical translation. Here, to address this concern we developed an amorphous solid dispersion of phloretin (Ph-SD) using Soluplus® as a polymer matrix. We further performed solid-state characterization through SEM, P-XRD, FT-IR, and TGA/DSC analysis. Phloretin content, encapsulation efficiency, and dissolution profile of the developed formulation were evaluated through reverse phase HPLC. Finally, the oral bioavailability of Ph-SD and its potential application in the treatment of experimental NAFLD mice was investigated. Results demonstrated that the developed formulation (Ph-PD) augments the dissolution profile and oral bioavailability of the native phloretin (Ph). In NAFLD mice, histopathological studies revealed the preventive effect of Ph-SD on degenerative changes, lipid accumulation, and inflammation in the liver. Ph-SD also improved the serum lipid profile, ALT, and AST levels and lowered the interleukin-6 and tumor necrosis factor-α levels in the liver. Further, Ph-SD reduced fibrotic changes in the liver tissues and attenuates NAFLD progression by blocking the mTOR/SREBP-1c pathway. In a nutshell, the results of our study strongly suggest that Ph-SD has the potential to be a therapeutic candidate in the treatment of NAFLD and can be carried forward for further clinical studies.

Amorphous Solid Dispersion as Drug Delivery Vehicles in Cancer

Cancer treatment has improved over the past decades, but a major challenge lies in drug formulation, specifically for oral administration. Most anticancer drugs have poor water solubility which can affect their bioavailability. This causes suboptimal pharmacokinetic performance, resulting in limited efficacy and safety when administered orally. As a result, it is essential to develop a strategy to modify the solubility of anticancer drugs in oral formulations to improve their efficacy and safety. A promising approach that can be implemented is amorphous solid dispersion (ASD) which can enhance the aqueous solubility and bioavailability of poorly water-soluble drugs. The addition of a polymer can cause stability in the formulations and maintain a high supersaturation in bulk medium. Therefore, this study aimed to summarize and elucidate the mechanisms and impact of an amorphous solid dispersion system on cancer therapy. To gather relevant information, a comprehensive search was conducted using keywords such as "anticancer drug" and "amorphous solid dispersion" in the PubMed, Scopus, and Google Scholar databases. The review provides an overview and discussion of the issues related to the ASD system used to improve the bioavailability of anticancer drugs based on molecular pharmaceutics. A thorough understanding of anticancer drugs in this system at a molecular level is imperative for the rational design of the products.

Hyperbranched Copolymers of Methacrylic Acid and Lauryl Methacrylate H-P(MAA-co-LMA): Synthetic Aspects and Interactions with Biorelevant Compounds

The synthesis of novel copolymers using one-step reversible addition-fragmentation chain transfer (RAFT) copolymerization of biocompatible methacrylic acid (MAA), lauryl methacrylate (LMA), and difunctional ethylene glycol dimethacrylate (EGDMA) as a branching agent is reported. The obtained amphiphilic hyperbranched H-P(MAA-co-LMA) copolymers are molecularly characterized by size exclusion chromatography (SEC), FTIR, and ¹H-NMR spectroscopy, and subsequently investigated in terms of their self-assembly behavior in aqueous media. The formation of nanoaggregates of varying size, mass, and homogeneity, depending on the copolymer composition and solution conditions such as concentration or pH variation, is demonstrated by light scattering and spectroscopic techniques. Furthermore, drug encapsulation properties are studied by incorporating the low bioavailability drug, curcumin, in the nano-aggregate hydrophobic domains, which can also act as a bioimaging agent. The interaction of polyelectrolyte MAA units with model proteins is described to examine protein complexation capacity relevant to enzyme immobilization strategies, as well as explore copolymer self-assembly in simulated physiological media. The results confirm that these copolymer nanosystems could provide competent biocarriers for imaging and drug or protein delivery/enzyme immobilization applications.

Development of a sorafenib-loaded solid self-nanoemulsifying drug delivery system: Formulation optimization and characterization of enhanced properties

Sorafenib, marketed under the brand name Nexavar®, is a multiple tyrosine kinase inhibitor drug that has been actively used in the clinical setting for the treatment of several cancers. However, the low solubility and bioavailability of sorafenib constitute a significant barrier to achieving a good therapeutic outcome. We developed a sorafenib-loaded self-nanoemulsifying drug delivery system (SNEDDS) formulation composed of capmul MCM, tween 80, and tetraglycol, and demonstrated that the SNEDDS formulation could improve drug solubility with excellent self-emulsification ability. Moreover, the sorafenib-loaded SNEDDS exhibited anticancer activity against Hep3B and KB cells, which are the most commonly used hepatocellular carcinoma and oral cancer cell lines, respectively. Subsequently, to improve the storage stability and to increase the possibility of commercialization, a solid SNEDDS for sorafenib was further developed through the spray drying method using Aerosil® 200 and PVP K 30. X-ray diffraction and differential scanning calorimeter data showed that the crystallinity of the drug was markedly reduced, and the dissolution rate of the drug was further improved in formulation in simulated gastric and intestinal fluid conditions. In vivo study, the bioavailability of the orally administered formulation increases dramatically compared to the free drug. Our results highlight the use of the solid-SNEDDS formulation to enhance sorafenib's bioavailability and outlines potential translational directions for oral drug development.

Drug-drug interactions associated with FLT3 inhibitors for acute myeloblastic leukemia: current landscape

INTRODUCTION

FLT3 inhibitors (FLT3i) are drugs in which there is limited experience and not yet enough information on the mechanisms of absorption, transport, and elimination; but especially on the potential drug-drug interactions (DDIs). There are therefore risks in the management of FLT3i DDIs (i.e. sorafenib, ponatinib, crenolanib, midostaurin, quizartinib, and gilteritinib) and ignoring them can compromise therapeutic success in acute myeloid leukemia (AML) treatment, in complex patients and secondary pathologies.

AREAS COVERED

This review summarizes the DDIs of FLT3i with P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), organic anion transporting (OAT), organic cationic transporting (OCT), cytochrome P450 (CYP) subunits, and other minor metabolic/transport pathways. EMBASE, PubMed, the Cochrane Central Register and the Web of Science were searched. The last literature search was performed on the 14 February 2022.

EXPERT OPINION

FLT3i will be combined with other therapeutic agents (supportive care, doublet, or triplet therapy) and in different clinical settings, which means a greater chance of controlling and even eradicating the disease effectively, but also an increased risk to patients due to potential DDIs. Healthcare professionals should be aware of the potential interactions that may occur and be vigilant in monitoring those patients who are receiving any potentially interacting drug.

Development of D-α-Tocopherol polyethylene glycol 1000 succinate fabricated nanostructural lipid carrier of sorafenib tosylate for metastatic colorectal targeting application: Stability, physical characterization, cytotoxicity, and apoptotic studies against SW48 cells PTEN

The study aimed to create D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) nanostructured lipid carriers (NLC) of sorafenib tosylate (ST) as lymphatic delivery systems (LDDS) to fight Metastatic colorectal cancer. Initially, ST-SLN, ST-NLC, and ST-LNE were formulated considering oleic acid (OA), glycerol monolinoleate (GMO), glycerol monolinoleate (GML) as solid lipid and further characterised, and tested for stability. The most stable ST-NLC was fabricated with TPGS to produce ST-TPGS-NLC and evaluated by performing in vitro drug profiling, in vitro cytotoxicity, and apoptotic studies against human female colorectal adenocarcinoma cell lines (SW48 Cells PTEN). Stability studies on three lipidic nanoparticles (ST-SLN, ST-NLC, ST-LEN) showed particle size, polydispersity index, and zeta potential ranging from 165 nm to 298 nm, 0.125 to 0.288, and -31 mV to -16 mV. At 1600 minutes, more than 80% of ST-NLC1 was released, confirming the sustained release pattern of the formulation. ST-NLC and ST-TPGS-NLC have entrapment efficiencies above 50%. Pure ST’s IC50 at 72 hr was 3.45 µg/mL, while 1.56 µg/mL was for ST-TPGS-NLC. The ST-TPGS-NLC reduced the number of livings SW48 Cells PTEN from 91% to 5%, compared to 75% to 8% of pure ST. The ST-TPGS-NLC is a promising LDDS for delivering ST for metastatic colorectal cancer.

Solid dispersions based on chitosan/hypromellose phthalate blends to modulate pharmaceutical properties of zidovudine

Zidovudine (AZT) has been widely used alone or in combination with other antiretroviral drugs for the treatment of human immunodeficiency virus. Its erratic oral bioavailability necessitates frequent administration of high doses, resulting in severe side effects. In this study, the design of mucoadhesive solid dispersions (SDs) based on chitosan (CS) and hypromellose phthalate (HP) was rationalized as a potential approach to modulate AZT physicochemical and pharmaceutical properties. SDs were prepared at different drug:polymer ratios, using an eco-friendly technique, which avoids the use of organic solvents. Particles with diameter from 56 to 73 µm and negative zeta potentials (-27 to -32 mV) were successfully prepared, achieving high drug content. Infrared spectroscopy revealed interactions between polymers but no interactions between the polymers and AZT. Calorimetry and X-ray diffraction analyses showed that AZT was amorphized into the SDs. The mucoadhesive properties of SDs were evidenced, and the control of AZT release rates from the matrix was achieved, mainly in acid media. The simple, low-cost and scalable technology proposed for production of SDs as a carrier platform for AZT is an innovative approach, and it proved to be a feasible strategy for modulation the physico-chemical, mucoadhesive and release properties of the drug.

Risk Assessment and QbD-Based Optimization of Sorafenib Tosylate Colon Targeted Bilayer Tablet: In Vitro Characterization, In Vivo Pharmacokinetic, and In Vivo Roentgenography Studies

The employment of site-specific administration in colon is a promising technique to improve efficacy and reduce systemic side effects of anticancer medications used in colorectal cancer. However, the physiology of the gastrointestinal tract and colonic environment limit the efficient delivery of orally administered anticancer drugs to the colon. These prerequisites can be fulfilled by a release modulated colon targeted drug delivery system (CTDDS) based on pH-dependent chronotherapeutic bilayer tablet of sorafenib tosylate (ST). Quality by design (QbD) was used to examine the risk assessment. The Box-Behnken design was used to optimize the core uncoated bilayer tablet, whereas the 2² factorial design was used to optimize the coating process. The amount of croscarmellose sodium, Eudragit^® RLPO, and tablet hardness all had a significant impact on disintegration time and drug release, according to the results of the core uncoated bilayer optimization. The amount of Eudragit^® S 100 and PEG 400 in the final coated tablet had a considerable impact on drug release. The optimized formulation demonstrated 5-h lag time, a peculiar feature of CTDDS. The pharmacokinetic studies of coated tablet in rabbits showed lower C_max (4.45 ± 0.40 µg/mL) and AUC (148.52 ± 3.96 h µg/mL), whereas T_max was substantially delayed (8.0 ± 0.57 h) compared to core uncoated tablet. The tablet remained intact until it reached the colon (> 4 h), according to the in vivo roentgenography studies. The present study revealed that a QbD approach can be useful to develop a rugged and scalable CTDDS.

Study on the Effect of Polymer Excipients on the Dispersibility, Interaction, Solubility, and Scavenging Reactive Oxygen Species of Myricetin Solid Dispersion: Experiment and Molecular Simulation

Although the preparation of amorphous solid dispersions can improve the solubility of crystalline drugs, there is still a lack of guidance on the micromechanism in the screening and evaluation of polymer excipients. In this study, a particular method of experimental characterization combined with molecular simulation was attempted on solubilization of myricetin (MYR) by solid dispersion. According to the analysis of the dispersibility and hydrogen-bond interaction, the effectiveness of the solid dispersion and the predicted sequence of poly(vinyl pyrrolidone) (PVP) > hypromellose (HPMC) > poly(ethylene glycol) (PEG) as the polymer excipient were verified. Through the dissolution, cell viability, and reactive oxygen species (ROS)-level detection, the reliability of simulation and micromechanism analysis was further confirmed. This work not only provided the theoretical guidance and screening basis for the miscibility of solid dispersions from the microscopic level but also served as a reference for the modification of new drugs.

A novel in vitro approach to investigate the effect of food intake on release profile of valsartan in solid dispersion-floating gel in-situ delivery system

Valsartan (VAL) is a BCS class II drug with low solubility and high permeability and, thus, its formulations often encounter low bioavailability problems. Its low bioavailability can be improved through enhanced formulation, such as incorporating it into a solid dispersion system (SD). The absorption can be further enhanced through gastroretentive systems. Herein, we developed a novel combination delivery approach consisting of floating in-situ gel and SD. VAL was incorporated with polymer carrier PVP and PEG 6000 and its solubility was then evaluated. The study found that VAL-SD containing PVP K-30 as the carrier with drug:PVP K-30 ratio of 1:3 shown highest solubility in different media. Moreover, DSC and XRD evaluations exhibited the change of VAL from crystal to amorphous following SD formulation. The SD was then formulated into floating in-situ gel preparations using sodium alginate as gel forming compound and HPMC as the controlled release matrix. The prepared VAL-SD floating in-situ gels were evaluated for their physical properties and drug release profile. The results showed that all physical evaluation of the floating in-situ gel formula possessed desirable physical properties and the use of HPMC in floating in-situ gel was able to sustain the in vitro release of VAL for 24 h in biorelevant media. Importantly, the effect of food intake on VAL release was also investigated, for the first time, showing that the VAL release could be controlled in FaSSGF (Fasted-State Simulated Gastric Fluid) in 2 h and FeSSGF (Fed-State Simulated Gastric Fluid) onwards. Thus, in can be hypothesized that the food intake did not affect the VAL release after 2 h in an empty gastric environment. Leading on from these results, in vivo studies in an animal model should be carried out to further assess the potency of this system.

Supersaturated LFCS type III self-emulsifying delivery systems of sorafenib tosylate with improved biopharmaceutical performance: QbD-enabled development and evaluation

The current studies investigate the application of quality by design-enabled type III self-emulsifying delivery system (Type III-SEDDS) of sorafenib tosylate (SFN) in improving its biopharmaceutical attributes. Initially, lipidic and emulsifying excipients were selected by carrying out solubility and phase titration experiments. After screening studies using Taguchi OA design, Type III-SEDDS were further optimised using D-optimal mixture design. The prepared formulations were assessed for globule size, zeta potential and percent of drug release. Following graphical optimisation, the optimum formulation was earmarked and further supersaturated to form saturated Type III-SEDDS (Sat-Type III-SEDDS) using a combination of HPMC and PVP to improve the stability of the formulation for a prolonged period. In vitro drug release of Type III-SEDDS study indicated approximately 8-fold improvement in dissolution rate over the pure powder drug. Cell uptake studies demonstrated higher uptake of dye-loaded Type III-SEDDS formulations in Caco-2 cells vis-à-vis plain dye. Cytotoxicity assay on Hep G2 cells revealed significant reduction in cell growth with Type III- and Sat-Type III-SEDDS vis-à-vis the pure drug. Furthermore, in situ permeation studies carried out using Wistar rats exhibited nearly 8.3- to 10.2-fold augmentation in permeation and absorption parameters of the drug from the Type III- and Sat-Type III-SEDDS, respectively, vis-à-vis the pure drug. Pharmacokinetic studies indicated nearly 3.98- and 3.62-fold improvement in AUC_0-72, and 8.01- and 5.42-fold in C_max, along with 0.25-fold decrease in T_max of the drug from Type III- and Sat-Type III-SEDDS, respectively, in comparison with the SFN suspension. Furthermore, high degree of level A linear correlation was established between fractions of drug dissolved (in vitro) and of drug absorbed (in vivo) at the corresponding time points for Sat-Type III-SEDDS and pure drug, whereas the Type III-SEDDS exhibited a nonlinear relationship. Stability studies indicated the robustness of Sat-Type III-SEDDS, when stored at 25 °C for 3 months. Overall, the manuscript documents the successful systematic development of SFN-loaded Sat-Type III-SEDDS with distinctly improved biopharmaceutical performance. Graphical abstract.

Preparation and characterization of sorafenib-loaded microprecipitated bulk powder for enhancing oral bioavailability

The aim of this study was to prepare and evaluate Eudragit-based microprecipitated bulk powder (MBP) formulations to enhance the oral bioavailability of sorafenib. Cationic Eudragit E PO and anionic Eudragit S100 were selected for MBP preparation. Ursodeoxycholic acid (UDCA)-incorporated MBP was also prepared to study the synergistic effect of UDCA in enhancing the bioavailability of sorafenib. Sorafenib-loaded MBPs were successfully prepared by a pH-controlled precipitation method using an aqueous antisolvent. Submicron-sized particles of MBPs were observed by scanning electron microscopy, and the amorphous form of sorafenib in MBPs was confirmed by powder X-ray diffraction. MBPs of cationic and anionic Eudragits showed different in vitro dissolution and pharmacokinetic profiles in rats. Sorafenib in Eudragit E PO-based MBP (E PO-MBP) was rapidly dissolved at low pH conditions (pH 1.2 and 4.0), but was precipitated again at pH 4.0 within 4 h. Dissolution of sorafenib from Eudragit S100-based MBP (S100-MBP) was high at pH 7.4 and did not precipitate for up to 4 h. After oral administration to rats, all MBPs, compared with powder, improved the oral absorption of sorafenib, with S100-MBP showing 1.5-fold higher relative oral bioavailability than E PO-MBP. Moreover, incorporation of UDCA in S100-MBP (S100-UDCA-MBP) further increased the C_max and oral bioavailability of sorafenib, although the dissolution was not significantly different from that of S100-MBP. Taken together, Eudragit-based MBP formulations could be a promising strategy for enhancing the oral bioavailability of sorafenib.

Characterizing and Exploring the Differences in Dissolution and Stability Between Crystalline Solid Dispersion and Amorphous Solid Dispersion

Solid dispersion is one of the most effective ways to improve the dissolution of insoluble drugs. When the carrier can highly disperse the drug, it will increase the wettability of the drug and reduce the surface tension, thus improving the solubility, dissolution, and bioavailability. However, amorphous solid dispersions usually have low drug loading and poor stability. Therefore, the goal of this work is to study the increased dissolution and high stability of high drug-loading crystalline solid dispersion (CSD), and the difference in dissolution and stability of high-loading and low-loading amorphous solid dispersion (ASD). A CSD of nimodipine with a drug loading of 90% was prepared by wet milling, with hydroxypropyl cellulose (model: HPC-SL) and sodium dodecyl sulfate as stabilizers and spray drying. At the same time, the gradient drug-loaded ASD was prepared by hot melt extrusion with HPC-SL as the carrier. Each preparation was characterized by DSC, PXRD, FT-IR, SEM, and in vitro dissolution testing. The results indicated that the drug in CSD existed in a crystalline state. The amorphous drug molecules in the low drug-loading ASD were uniformly dispersed in the carrier, while the drug state in the high drug-loading ASD was aggregates of the amorphous drug. At the end of the dissolution assay, the 90% drug-loading CSD increased cumulative dissolution to 60%, and the 10% drug-loading ASD achieved a cumulative dissolution rate of 90%.

Enhanced Dissolution of Luteolin by Solid Dispersion Prepared by Different Methods: Physicochemical Characterization and Antioxidant Activity

Luteolin (LT) is a poorly soluble bioactive compound that suffered bioavailability problems after oral administration. Hence, the aim of the proposed research work was to formulate and investigate various solid dispersions (SDs) of LT in order to enhance its dissolution and bioactivity. LT-SD was prepared using polyethylene glycol 4000 (PEG 4000) as a carrier at the mass ratios of 1:1, 1:2, and 1:4. LT-SD was prepared using different methods including fusion (FU), solvent evaporation (SE), and microwave irradiation (MI) methods. The prepared LT-SD was duly characterized in terms of differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared (IR) spectroscopy, and nuclear magnetic resonance (NMR) and evaluated for dissolution and in vitro antioxidant activity. The results of DSC, XRD, SEM, IR, and NMR suggested the formation of LT-SD. After 90 min of the dissolution study, the results displayed that the % release of LT from prepared SD was significantly higher compared with the pure LT and its physical mixture dispersion (PMD). LT-SD prepared using the MI method displayed the maximum release of LT (i.e., 97.78 ± 4.41%) at a 1:2 mass ratio of LT:PEG 4000. The LT-SD prepared using the SE method displayed the maximum release of 93.78 ± 3.98% at a mass ratio of 1:4 of LT:PEG 4000. The SD prepared by the MI method showed enhanced dissolution due to higher aqueous solubility and the reduction of particle size. The solid-state characterization studies (DSC, XRD, SEM, IR, and NMR studies) suggested the morphological conversion of LT into the amorphous form from the crystalline state. The results of the antioxidant study revealed that the formation LT-SD displayed significantly higher radical scavenging activity than the pure LT. Therefore, SD obtained using PEG 4000 could be a potential strategy for maximizing the solubility, in vitro dissolution, and therapeutic efficacy of LT.

Microfluidic fabrication and characterization of Sorafenib-loaded lipid-polymer hybrid nanoparticles for controlled drug delivery

Lipid polymer hybrid nanoparticles (LPHNPs) have been merged as potential nanocarriers for treatment of cancer. In the present study, LPHNPs loaded with Sorafenib (SFN) were prepared with PLGA, Lecithin and DSPE-PEG 2000 by using the bulk nanoprecipitation and microfluidic (MF) co-flow nanoprecipitation techniques. Herein, a glass capillary microfluidic device was primed to optimize the LPHNPs and compared to the bulk nanoprecipitation method. The morphological analysis of prepared LPHNPs revealed the well-defined spherical nano-sized particles in bulk nanoprecipitation method. Whereas, core shell morphology was observed in the MF method. The formulation prepared by the MF method (MF1-MF3) indicated relatively higher % EE (95.0%, 93.8% and 88.7%) and controlled release of the SFN from the particles as compared to the LPHNPs obtained by the bulk nanoprecipitation method. However, the release of SFN from all LPHNP formulation followed Higuchi model (R² = 0.9901-0.9389) with Fickian diffusion mechanism. Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and powder X-rays diffraction (pXRD) studies depicted the compatibility of SFN with all the structural components. In addition, the colloidal stability, in vitro cytotoxicity and cell growth inhibition studies of LPHNPs also demonstrated stability in biological media, biocompatibility and safety with enhanced anti-proliferative effects than the free SFN in breast cancer and prostate cancer cells. In conclusion, LPHNPs provided a prospective platform for the cancer chemotherapy and substantially improved the knowledge of fabrication and optimization of the hybrid nanoparticles.

Spray-Dried Amorphous Solid Dispersions of Griseofulvin in HPC/Soluplus/SDS: Elucidating the Multifaceted Impact of SDS as a Minor Component

This study aimed to elucidate the impact of a common anionic surfactant, sodium dodecyl sulfate (SDS), along with hydroxypropyl cellulose (HPC) and Soluplus (Sol) on the release of griseofulvin (GF), a poorly soluble drug, from amorphous solid dispersions (ASDs). Solutions of 2.5% GF and 2.5%–12.5% HPC/Sol with 0.125% SDS/without SDS were prepared in acetone–water and spray-dried. The solid-state characterization of the ASDs suggests that GF–Sol had better miscibility and stronger interactions than GF–HPC and formed XRPD-amorphous GF, whereas HPC-based ASDs, especially the ones with a lower HPC loading, had crystalline GF. The dissolution tests show that without SDS, ASDs provided limited GF supersaturation (max. 250%) due to poor wettability of Sol-based ASDs and extensive GF recrystallization in HPC-based ASDs (max. 50%). Sol-based ASDs with SDS exhibited a dramatic increase in supersaturation (max. 570%), especially at a higher Sol loading, whereas HPC-based ASDs with SDS did not. SDS did not interfere with Sol’s ability to inhibit GF recrystallization, as confirmed by the precipitation from the supersaturated state and PLM imaging. The favorable use of SDS in a ternary ASD was attributed to both the wettability enhancement and its inability to promote GF recrystallization when used as a minor component along with Sol.

Sustained Release Ziprasidone Microparticles Prepared by Spray Drying with Soluplus® and Ethyl Cellulose to Eliminate Food Effect and Enhance Bioavailability

The purpose of this study was to develop and evaluate a new formulation of ziprasidone (ZIP) for improved fasted state absorption and sustained drug release. ZIP solid dispersions were produced via spray drying using Soluplus®, an amphiphilic polymer, as the solubility enhancer. Physicochemical analysis proved that ZIP presented at amorphous state in the spray-dried microparticles and the dissolution rate of ZIP from the Soluplus®-ZIP composite microparticles was significantly increased compared with that of the physical mixtures. Commonly used encapsulation materials including Eudragit® RL, Eudragit® S100 and Ethyl Cellulose were incorporated into the solid dispersions to regulate the drug release kinetics. The formulation containing ethyl cellulose provided the most sustained release behaviors. Pharmacokinetic studies in beagle dogs confirmed that there was no significant difference in oral bioavailability of the microparticles under fasted and fed states, and a prolonged T_max value was simultaneously achieved compared with the commercial ZIP capsules.

Improving the Dissolution of Triclabendazole from Stable Crystalline Solid Dispersions Formulated for Oral Delivery

Triclabendazole belongs to the class II/IV of the Biopharmaceuticals Classification System, and its low aqueous solubility represents a major drawback during the development of effective dosage forms. Therefore, the goal of this study was to elucidate whether polymeric solid dispersions would represent a suitable approach to overcome such disadvantage. Due to the lack of information on triclabendazole release, four different dissolution media were evaluated to analyze drug dissolution rate. The polymeric solid dispersions were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The selected final formulations were further stored for 24 months, and their physical stability was evaluated by means of X-ray diffraction and drug dissolution assays. Drug solubility studies indicated that poloxamer 407 (P407) solubilized a higher amount of drug than polyethylene glycol 6000. Drug-to-carrier ratio, nature of the selected carriers, and the type of dissolution media were important factors for increasing dissolution. By infrared spectroscopy, there were no specific interactions between the drug and polymers. The physicochemical characterization of the systems showed a detectable evidence of drug amorphization by increasing the carrier ratio. Micromeritic studies indicated that raw triclabendazole, physical mixtures, and reference formulation showed poor flow properties, in contrast to the triclabendazole:P407 solid dispersion sample. Both the crystalline properties and dissolution rate of selected samples were very similar after 24 months at room temperature. Thus, considering physical stability and dissolution studies, the development of the solid dispersion is a very suitable methodology to improve triclabendazole dissolution and, potentially, its biopharmaceutical performance.

Harnessing the therapeutic potential of anticancer drugs through amorphous solid dispersions

The treatment of cancer is still a major challenge. But tremendous progress in anticancer drug discovery and development has occurred in the last few decades. However, this progress has resulted in few effective oncology products due to challenges associated with anticancer drug delivery. Oral administration is the most preferred route for anticancer drug delivery, but the majority of anticancer drugs currently in product pipelines and the majority of those that have been commercially approved have inherently poor water solubility, and this cannot be mitigated without compromising their potency and stability. The poor water solubility of anticancer drugs, in conjunction with other factors, leads to suboptimal pharmacokinetic performance. Thus, these drugs have limited efficacy and safety when administered orally. The amorphous solid dispersion (ASD) is a promising formulation technology that primarily enhances the aqueous solubility of poorly water-soluble drugs. In this review, we discuss the challenges associated with the oral administration of anticancer drugs and the use of ASD technology in alleviating these challenges. We emphasize the ability of ASDs to improve not only the pharmacokinetics of poorly water-soluble anticancer drugs, but also their efficacy and safety. The goal of this paper is to rationalize the application of ASD technology in the formulation of anticancer drugs, thereby creating superior oncology products that lead to improved therapeutic outcomes.

Overview of the Manufacturing Methods of Solid Dispersion Technology for Improving the Solubility of Poorly Water-Soluble Drugs and Application to Anticancer Drugs

Approximately 40% of new chemical entities (NCEs), including anticancer drugs, have been reported as poorly water-soluble compounds. Anticancer drugs are classified into biologic drugs (monoclonal antibodies) and small molecule drugs (nonbiologic anticancer drugs) based on effectiveness and safety profile. Biologic drugs are administered by intravenous (IV) injection due to their large molecular weight, while small molecule drugs are preferentially administered by gastrointestinal route. Even though IV injection is the fastest route of administration and ensures complete bioavailability, this route of administration causes patient inconvenience to visit a hospital for anticancer treatments. In addition, IV administration can cause several side effects such as severe hypersensitivity, myelosuppression, neutropenia, and neurotoxicity. Oral administration is the preferred route for drug delivery due to several advantages such as low cost, pain avoidance, and safety. The main problem of NCEs is a limited aqueous solubility, resulting in poor absorption and low bioavailability. Therefore, improving oral bioavailability of poorly water-soluble drugs is a great challenge in the development of pharmaceutical dosage forms. Several methods such as solid dispersion, complexation, lipid-based systems, micronization, nanonization, and co-crystals were developed to improve the solubility of hydrophobic drugs. Recently, solid dispersion is one of the most widely used and successful techniques in formulation development. This review mainly discusses classification, methods for preparation of solid dispersions, and use of solid dispersion for improving solubility of poorly soluble anticancer drugs.

Influence of Polymers on the Physical and Chemical Stability of Spray-dried Amorphous Solid Dispersion: Dipyridamole Degradation Induced by Enteric Polymers

Amorphous solid dispersions (ASDs) are inherently unstable because of high internal energy. Evaluating physical and chemical stability during the process and storage is essential. Numerous researches have demonstrated how polymers influence the drug precipitation and physical stability of ASDs, while the influence of polymers on the chemical stability of ASDs is often overlooked. Therefore, this study aimed to investigate the effect of polymers on the physical and chemical stability of spray-dried ASDs using dipyridamole (DP) as a model drug. Proper polymers were selected by assessing their abilities to inhibit drug recrystallization in supersaturated solutions. HPMC E5, Soluplus®, HPMCP-55, and HPMCAS-LP were shown to be effective stabilizers. The optimized formulations were further stored at a high temperature (60 °C) and high humidity (40 °C, 75% RH) for 2 months, and their physical and chemical stability was evaluated using polarizing optical microscopy, FTIR, HPLC, and mass spectrometry (MS). In general, crystallization was observed in all samples, which indicated the physical instability under stressed storage conditions. Also, it was noted that the polymers in ASDs rather than physical mixtures, induced a dramatic drug degradation after being exposed to a high temperature (HPMCP-55 > 80% and HPMCAS-LP > 50%) and high humidity (HPMCP-55 > 40% and HPMCAS-LP > 10%). The MS analysis further confirmed the degradation products, which might be generated from the reaction between dipyridamole and phthalic anhydride decomposed from HPMCP-55 and HPMCAS-LP. Overall, the exposure of ASDs to stressed conditions resulted in recrystallization and even the chemical degradation induced by polymers.

Fabrication of poly (butadiene-block-ethylene oxide) based amphiphilic polymersomes: An approach for improved oral pharmacokinetics of Sorafenib

Sorafenib (SFN), a hydrophobic anticancer drug, has several limitations predominantly poor aqueous solubility and hepatic first-pass effect, limiting its oral delivery that results into several other complications. Present study aims to develop Sorafenib loaded polymersomes using poly butadiene block poly ethylene oxide (PB-b-PEO), an amphiphilic co-block polymer. Prior to drug loading, critical aggregate concentration (CAC) of polymer was calculated for stable formulation synthesis. The developed SFN loaded PB-b-PEO polymersomes (SFN-PB-b-PEO, test formulation) characterized by DLS and cryo-TEM showed particle size 282 nm, polydispersity (PDI) of less than 0.29 and membrane thickness of about 20 nm. SFN-PB-b-PEO polymersomes demonstrated encapsulation efficiency of 71% and showed sustained drug release up to 144 h. Formulation remained stable for 3 months in suspension form. In vitro cytotoxicity against HepG2 cells showed 1.7 folds improved toxicity compared to SFN suspension. In addition, oral administration of SFN-PB-b-PEO polymersomes in BALB/c mice showed increased C_max and AUC_0-96 by 1.7 and 2.77-fold respectively (p < 0.05) compared to those of SFN suspension (reference formulation). Findings suggest that the SFN-PB-b-PEO polymersomes can be a potential candidate for oral delivery of SFN.

Soluplus micelles for improving the oral bioavailability of scopoletin and their hypouricemic effect in vivo

Scopoletin is an active coumarin possessing a variety of pharmacological activities, including anti-hyperuricemic effect, but with poor solubility. To improve its oral bioavailability, we attempted to encapsulate scopoletin into Soluplus micelles (Soluplus-based scopoletin micelles, Sco-Ms) and evaluated the hypouricemic action of Sco-Ms. Sco-Ms were prepared using a thin-film hydration method. Sco-Ms displayed near spherical shapes with an average size of 59.4±2.4 nm (PDI=0.08±0.02). The encapsulation efficiency of scopoletin was 87.3%±1.5% with a loading capacity of 5.5%±0.1%. Sco-Ms were further characterized using transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared techniques and scanning electron microscopy. After oral administration in rats, Sco-Ms exhibited significantly improved absorption in each intestinal segment compared to free scopoletin, with the duodenum and jejunum being the main absorption regions. In rats administered Sco-Ms (at an equivalent dose of free scopoletin of 100 mg/kg, po), the AUC_0-∞ and C_max of Sco-Ms were 4.38- and 8.43-fold, respectively, as large as those obtained following administration of free scopoletin. After oral administration in rats, Sco-Ms did not alter the tissue distributions of scopoletin, but significantly increased the scopoletin levels in the liver. In potassium oxonate-induced hyperuricemic mice, oral administration of Sco-Ms (at an equivalent dose of free scopoletin of 300 mg/kg) reduced the serum uric acid concentration to the normal level. The results suggest that Soluplus-based micelle system greatly improves the bioavailability of poorly water-soluble drugs, such as scopoletin, and represents a promising strategy for their oral delivery.

Characterization, Molecular Docking, and In Vitro Dissolution Studies of Solid Dispersions of 20(S)-Protopanaxadiol

In this study, we prepared solid dispersions (SDs) of 20(S)-protopanaxadiol (PPD) using a melting-solvent method with different polymers, in order to improve the solubility and dissolution performance of drugs with poor water solubility. The SDs were characterized via differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and molecular docking and dynamics study. DSC and PXRD results indicated that PPD crystallinity in SDs was significantly reduced, and that the majority of PPD is amorphous. No interaction was observed between PPD and polymers on FTIR and NMR spectra. Molecular docking and dynamic calculations indicated that the PPD molecule localized to the interpolated charged surface, rather than within the amorphous polymer chain network, which might help prevent PPD crystallization, consequently enhancing the PPD dispersion in polymers. An in vitro dissolution study revealed that the SDs considerably improved the PPD dissolution performance in distilled water containing 0.35% Tween-80 (T-80). Furthermore, among three PPD-SDs formulations, Poloxamer188 (F68) was the most effective in improving the PPD solubility and was even superior to the mixed polymers. Therefore, the SD prepared with F68 as a hydrophilic polymer carrier might be a promising strategy for improving solubility and in vitro dissolution performance. F68-based SD, containing PPD with a melting-solvent preparation method, can be used as a promising, nontoxic, quick-release, and effective intermediate for other pharmaceutical formulations, in order to achieve a more effective drug delivery.

High-Energy Ball Milling as Green Process To Vitrify Tadalafil and Improve Bioavailability

In this study, the suitability of high-energy ball milling was investigated with the aim to vitrify tadalafil (TD) and improve its bioavailability. To achieve this goal, pure TD as well as binary mixtures composed of the drug and Soluplus (SL) were coprocessed by high-energy ball milling. Modulated differential scanning calorimetry (MDSC) and X-ray powder diffraction (XRD) demonstrated that after such coprocessing, the crystalline form of TD was transformed into an amorphous form. The presence of a single glass transition (T_g) for all the comilled formulations indicated that TD was dispersed into SL at the molecular level, forming amorphous molecular alloys, regardless of the drug concentration. The high values of T_g determined for amorphous formulations, ranging from 70 to 147 °C, foreshow their high stability during storage at room temperature, which was verified by XRD and MDSC studies. The stabilizing effect of SL on the amorphous form of TD in comilled formulations was confirmed. Dissolution tests showed immediate drug release with sustained supersaturation in either simulated gastric fluid of pH 1.2 or in phosphate buffer of pH 7.2. The beneficial effect of both amorphization and coamorphization on the bioavailability of TD was found. In comparison to aqueous suspension, the relative bioavailability of TD was only 11% for its crystalline form and 53% for the crystalline physical mixture, whereas the bioavailability of milled amorphous TD and the comilled solid dispersion was 128% and 289%, respectively. Thus, the results provide evidence that not only the presence of polymeric surfactant but also the vitrification of TD is necessary to improve bioavailability.

Solubilization and formulation of chrysosplenol C in solid dispersion with hydrophilic carriers

We investigated how to overcome problems associated with the solubility, dissolution, and oral bioavailability of the poorly water-soluble drug compound, chrysosplenol C (CRSP), as well as the effects of single and binary hydrophilic polymers (PVP K-25 and/or PEG 6000) on the solubility and dissolution parameters of CRSP. Then an optimized formulation was further developed with a surfactant. To select a surfactant suitable for a CRSP-loaded solid dispersion (SD), the solubility of CRSP in distilled water containing 1% surfactant was compared with the solubilities in other surfactants. Sodium lauryl sulfate (SLS) showed the highest drug solubility. Overall, a formulation containing CRSP, binary hydrophilic polymers (PVP and PEG 6000), and SLS at a ratio of 2.0/0.2/1.1/0.7 showed the optimum in vitro release profile. This optimized formulation had better safety properties than pure CRSP in cell viability examinations. SD formulations were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy. Our optimized SD formulation is expected to improve the bioavailability of CRPS because it improves the solubility and dissolution rate of CRSP.

Inherent formulation issues of kinase inhibitors

The small molecular Kinase Inhibitor (smKI) drug class is very promising and rapidly expanding. All of these drugs are administered orally. The clear relationship between structure and function has led to drugs with a general low intrinsic solubility. The majority of the commercial pharmaceutical formulations of the smKIs are physical mixtures that are limited by the low drug solubility of a salt form. This class of drugs is therefore characterized by an impaired and variable bioavailability rendering them costly and their therapies suboptimal. New formulations are sparingly being reported in literature and patents. The presented data suggests that continued research into formulation design can help to develop more efficient and cost-effective smKI formulation. Moreover, it may also be of help in the future design of the formulations of new smKIs.